243 Cigarettes
by Isefyr
Summary: Sherlock sets out to catalog the properties of cigarettes and their ash. The resultant experiment tries everyone's patience, fills 221b with smoke, and drives John insane - but it also leads to a discovery that nobody saw coming. Warning for smoking? Like, ridiculous amounts. Do not try this at home.


**243 cigarettes**

 **(alternately titled** _ **where there's ash, there's been a spark**_ **)**

 **...**

Sherlock Holmes is interested in gathering information. A vast base of knowledge makes deduction that much more efficient, especially if your talents are needed on a _hurry-up-before-the-next-one-is-murdered_ sort of basis.

However, the information has to be _relevant._ What kind of use is the knowledge of the solar system, to one who is solving earthly mysteries? And who, really, needs to know _any_ song lyrics, let alone the national anthem?

Thus, Sherlock spends his time – when he's not on a case – gathering _interesting, relevant_ information – like in-depth analysis of over 200 types of cigarette ash.

Which means he's going to personally smoke over 200 varied cigarettes. He doesn't mind, as nicotine helps him think, and after all, it's going to be very useful.

He wonders if his flat-mate will mind…

…

 _#198 – Camel, Turkish Gold_

 _Room note- John wondered if I'd used mouthwash to try to cover up that I'd been smoking. Will not use this blend again as am not trying to emulate a guilty teenager._

…

Apparently, his flat-mate does mind. John, after walking into 221b after tests #1 through #27, wrinkles his nose and heads straight to open the window.

"Look, I understand you need the nicotine to think," he says, voice somewhat muted as his head is sticking out the window, "But do you think that you could try to keep the flat smelling a bit less like a fire at a chemical plant?"

"It's for research!" Sherlock says, furiously.

John pauses, and Sherlock hopes that John is being swayed by Sherlock's appeal. After all, John does seem to delight in deduction, and experiments are a step towards deduction…

John opens his mouth to say something, gets a lungful of 27 types of smoke, and starts to cough. Sherlock gets the feeling that his research might not be appreciated.

…

 _#46 – Honeydew leaf_

 _Room note – I thought it was rather pleasant. John, however, insisted it was very strong and shooed me out of the flat so that he could spray air freshener everywhere. Now the flat smells like "Mountain Spring" and I can't_ think _properly._

…

Sherlock is shocked to find that _nobody_ appreciates his research.

He shows up to a crime scene after #43 and finds Lestrade frowning at him like a mother hen. One of the techs, however, is bold enough to say it – "did you set your flat on fire?"

"No," Sherlock says, shortly, crouching over the body. He's so annoyed that when John shows up, he doesn't explain any of his deductions out loud. Not even when John looks at him with puppy eyes. Nope.

He's smoking cigarettes for _science_. Or something.

"You should be glad I'm not testing blood spatter," Sherlock grumbles apropos of nothing, and John gives him a small smile, but stays upwind.

…

 _#119 – Navy-cut Maverick_

 _Room note – John pretended not to like this one, but it's growing on him. I can tell. His excuse to leave the flat was a sham, as we already have milk. Thus, he must have gone to remove himself from temptation._

…

Mrs. Hudson does her best to stop him next, claiming that she'll never rent the final flat if the entire building constantly smells of smoke.

"And anyway, dear, it's in your contract that you're not supposed to smoke," she says while bringing him a cup of tea.

John, at this point, is somewhat resigned to the experiment. "It's also probably in his contract that he's not supposed to keep body parts in the fridge," he says from behind his laptop. "He doesn't follow that either."

Mrs. Hudson shakes her head in a loving but totally exasperated sort of manner.

"If you get the floor all corpse-y," she says, " _I'm not cleaning it up_."

"No," John sighs, "That'll be me."

Sherlock smirks.

…

 _#77 – Parliament Lite_

 _Room note – John is getting sneakier. Was smoking this one in secret when John discovered me. Chucked the cigarette out the window, but John distracted me by getting very close,_ invading my personal space, _basically breathing the same air as I was... He wasn't pleased when he smelled smoke. (Either on my breath, or because I missed the window and almost set the curtain on fire)._

 **...**

"Are you trying to tell me something?" John asks one day, sounding wounded, as he finds the remnants of #88, #92, and #93 in the dustbin. "Are you trying to _literally_ smoke me out of 221b?"

Sherlock doesn't even look up from the ash of #95 under his microscope. "Why would you think that?" he drawls.

"Because, if anything, your pace has increased, and if I come home one day to find you've smoked 27 in a row again, I'm quite frankly considering moving out. Do you _realize_ how expensive all the air freshener is getting?"

Sherlock looks up at John's distressed face and blinks. He doesn't want John to leave. His experiment is important – regardless of the naysayers – but he has also just discovered that it's important to him that John stays right where he is.

"Hmmm," he replies, looking back down at his work. John huffs and stomps away to get some fresh air.

(Sherlock does, however, scale his intake back to only 1 a day.)

…

 _#210 – Cavendish_

 _Room note- Though it's become difficult to tell one from another, this blend has won the distinction of 'Quickest to Set Mistletoe on Fire'. I'm not sure why John isn't speaking to me, as the sweater he was wearing was quite awful._

…

"Sherlock," Lestrade asks one day after Sherlock's caught the criminal for them _again_ , "Are you almost done this …experiment of yours?"

"I'm on the last few," Sherlock says, busying himself with his coat collar. "I didn't think it was of any importance to you."

"Well-" Lestrade hesitates. "I think maybe you ought to hurry it up."

"It's _science_ ," Sherlock said, incensed, "And you want me to _hurry it up?_ "

"I think," Lestrade says, shooing Sherlock out of his office, "You'll find that some of us have been waiting _very patiently_ for this experiment to end."

Sherlock opens his mouth, but Lestrade is closing his door. "Maybe you should talk to John. I'm sure he can find something suitably _entertaining_ for you to do."

The door has shut, and Sherlock is actually speechless.

He burns through #213-#216 in an effort to figure out what Lestrade meant, but it doesn't help.

…

 _#52 – Djarum Black Clove_

 _Room note – John actually thought I was baking gingerbread when I smoked this. His deduction skills need some work._

…

The experiment has to wait for a little while when Sherlock is distracted by a serial killer. John is thrilled and annoyed and worried – thrilled that there's a pause to Sherlock's incredible feats of chain smoking, annoyed that it's going to take even _longer_ to reach the conclusion of the experiment, and worried… Sherlock isn't sure why he's worried.

John seems to be more and more antsy when Sherlock takes on cases that might be a little… dangerous. Sherlock wonders if he's going through a hormonal change or something. Sherlock wonders a lot of things, but none of them are exactly relevant to his work, so he pushes them out of mind.

The killer is apprehended after a long chase through the London Underground, which also results in numerous bruises, a bloody nose (on John's part) and split knuckles (on Sherlock's part). When the police _finally_ show up, Sherlock thrusts the killer into their care and turns to check on John's nose.

"Is it broken?" he asks, shaking out a handkerchief and carefully cupping John's face with it. John shakes his head and puts his hand over Sherlock's, ostensibly to take the handkerchief from him, but something shorts out in Sherlock's brain and he doesn't let go.

"It's alright, Sherlock," John says, sounding a little muffled, and Sherlock carefully pulls his hand away.

(There's something teasing the edge of his consciousness. He thinks he needs a cigarette.)

…

 _#223 – Du Maurier Blue_

 _Room note – This one was rather pleasant, in my opinion. What was not pleasant was the discovery that John is counting down the days until my experiment is finished._

 _I've considered adding some that are illegal in the UK… but John's nose is still broken so I might take the high road. Purely for health reasons of course._

…

Finally, Sherlock is done. He's smoked all the different types of cigarettes he found necessary and filed all the information away. He feels extraordinarily proud of himself – what a great leap for deductive reasoning!

John kicks him out of the flat when he's done, to clean with a vengeance (and, Sherlock suspects, to toss any remaining cigarettes out). Sherlock, feeling wounded that nobody is celebrating the completion of his experiment, mopes around the neighborhood until John texts him the OK.

He comes back into the flat and finds John sitting in his usual chair, clutching what looks like a peachy-beige square.

"What is that?"

John holds out the square. "This is a nicotine patch."

Sherlock takes the patch, curious. It seems to adhere to skin as a form of delivery. Very practical.

"I know you need nicotine to focus, sometimes," John says, standing up. "And because I don't want a repeat of the Great Cigarette Experiment, I thought you could try these."

Sherlock is studying the patch closely. Is this what Lestrade meant? It's not exactly a great discovery.

He looks up to ask John about it, but his flatmate has already gotten up to make tea.

…

 _#61 – Lambert & Butler_

 _Room note – Quite pungent and sharp. John did not return to the flat. I find this disturbing._

…

Sherlock is bored. Bored, bored, bored. With the loss of the Great Cigarette Experiment – and the resultant whinging and sneaky attempts by his flat mate to get him to _stop_ the Great Cigarette Experiment – he has nothing to do.

He has actually stooped _so low_ that he's watching the _telly_ with John and Mrs. Hudson. It's some soap opera, and he's only halfway paying attention. The other half of his brain is cataloguing the burn marks on the ceiling and wondering if anyone would notice another one.

Perhaps there's a brand that he missed…

A movement on the screen catches his attention. Two of the characters whose names Sherlock cannot remember are standing under the mistletoe, looking up at it with transfixed expressions. Then, they approach each other, turning their heads slightly, and press their lips together. By the cooing coming from John and Mrs. Hudson, Sherlock presumes that this is a desirable action.

What is it, though? And how does it work?

From John and Mrs. Hudson's excited chatter, Sherlock deduces that this action is called _kissing_ , that it's something that many people enjoy – more, on average, than people enjoy smoking.

Thus, it must be more relevant to deduction…

Eyeing John carefully and doing calculations in his head – height ratios, head positions - Sherlock is beginning to get an idea for his next experiment.

He wonders if there's more than one _type_ of kiss.

…

 _#1 – first kisses_

 _Room note: John liked it. So did I._

…

 **A/N:**

 **1\. I don't own Sherlock Holmes - in** _ **any**_ **of his incarnations.**

 **2a. This is not really accurate to the BBC timeline, and  
2b. I know absolutely nothing about tobacco, but**

 **3\. I hope you enjoyed this anyways!**

 **-Isefyr**


End file.
